diff --git a/src/brevitas/backport/fx/immutable_collections.py b/src/brevitas/backport/fx/immutable_collections.py
index 0144e4701..b848bf1cf 100644
--- a/src/brevitas/backport/fx/immutable_collections.py
+++ b/src/brevitas/backport/fx/immutable_collections.py
@@ -43,7 +43,12 @@
 
 from typing import Any, Dict, List, Tuple
 
-from torch.utils._pytree import _register_pytree_node
+try:
+    from torch.utils._pytree import register_pytree_node
+except:
+    # Deprecated as of 2.3, but keeping for backportability
+    from torch.utils._pytree import _register_pytree_node
+    register_pytree_node = _register_pytree_node
 from torch.utils._pytree import Context
 
 from ._compatibility import compatibility
@@ -111,5 +116,5 @@ def _immutable_list_unflatten(values: List[Any], context: Context) -> List[Any]:
     return immutable_list(values)
 
 
-_register_pytree_node(immutable_dict, _immutable_dict_flatten, _immutable_dict_unflatten)
-_register_pytree_node(immutable_list, _immutable_list_flatten, _immutable_list_unflatten)
+register_pytree_node(immutable_dict, _immutable_dict_flatten, _immutable_dict_unflatten)
+register_pytree_node(immutable_list, _immutable_list_flatten, _immutable_list_unflatten)